Emergency lighting systems are dependent on battery backup to provide egress lighting when AC power has failed. Presently, emergency lighting units are provided with manual test capability. Typically, these units provide a test switch, or other manual means for initiating a test, which is held in the “ON” position for 90 seconds each month. The battery is tested by applying a load for the duration in which the switch is pressed.
This method of battery test is inadequate to properly measure actual battery capacity. For example, a given unit loads the battery with 1 Ampere during the 90 second load test. This is the same as the emergency lighting load. This load represents only a 0.025 Ampere-hour (Ah) discharge, and is not really an adequate representation of battery condition, since the actual system will be required to provide 90 minutes standby. Additionally, an annual test is intended to be done in order to measure actual battery capacity by fully discharging the batteries. This test requires significant labor, since a building can have many emergency lighting components.
U.S. Pat. No. 6,538,568, to Conley III, entitled “EMERGENCY LIGHTING REMOTE MONITORING AND CONTROL SYSTEM” teaches an emergency lighting unit identified by unique ID numbers. The unit communicates via wireless means with a central controller. Various commands from the central controller may include turning the lamp on and off, requesting a status, or initiating a battery voltage and lamp current tests.